The Integrated Carbohydrate Physiology and Translation Laboratory offers several laboratory services for other researchers.
These services are available to collaborators both within and outside of Mayo Clinic. Contact the lab for more information about each service and the cost.
- Glucose clamps: Euglycemic, hypoglycemic and hyperglycemic
These tests are designed to accurately measure insulin sensitivity in a person with or without diabetes.
The technique involves infusing insulin intravenously at a constant rate over a few hours while maintaining blood glucose concentrations at a predetermined concentration depending on the specific scientific questions posed.
Advancements in the methodology developed by Robert A. Rizza, M.D., of Mayo Clinic's campus in Rochester, Minnesota, and refined by the laboratory include simultaneous infusion of glucose tracers to partition insulin sensitivity into peripheral (muscle) or hepatic (liver) components.
Infusing the hormone somatostatin simultaneously permits fine-tuning insulin concentrations so that the insulin sensitivity parameters can be compared between research study cohorts, for example, people with type 2 diabetes and people without diabetes.
Description: Regulation of hyperglycemia, euglycemia and hypoglycemia
- Oral glucose tolerance test
This physiologically pertinent method involves administering a 75-gram glucose drink together with periodic measurement of glucose and pertinent hormone concentrations (insulin, C peptide, glucagon, glucagon-like peptide 1) for two to three hours.
This method, coupled with physiological modeling developed in conjunction with mathematicians, provides measures of insulin secretion and insulin sensitivity.
Use of glucose tracers in the glucose drink could also help in partitioning of insulin sensitivity indexes.
Description: Measurement of the body's ability to metabolize glucose
- Intravenous glucose tolerance test
This method involves administering an intravenous glucose infusion followed, if necessary, by an insulin bolus, together with periodic measurement of glucose and pertinent hormone concentrations (insulin, C peptide, glucagon) for two to three hours.
This glucose tolerance test, coupled with physiological modeling developed in conjunction with mathematicians, provides measures of insulin secretion and insulin sensitivity.
Use of glucose tracers allows partitioning of insulin sensitivity indexes. A combination of both the oral glucose tolerance test (OGTT) and an intravenous glucose tolerance test (IVGTT) with an isoglycemic clamp (matching the glucose concentrations achieved during OGTT with an intravenous glucose infusion) could also provide valuable insight into the role of the incretin hormone GLP-1 on insulin secretion.
Description: Isoglycemic clamp
- Mixed meal tests
This state-of-the-art methodology involves use of three different glucose tracers during a measured mixed meal test.
A research participant ingests a mixed meal containing glucose labeled with a glucose tracer while two other glucose tracers are infused intravenously at variable rates for six to seven hours.
During this time, periodic blood samples are drawn for measuring glucose, glucose tracer and hormone concentrations.
The data obtained can be used to measure insulin secretion and liver and peripheral insulin sensitivity.
This method for the mixed meal test is the most physiologically natural and relevant method that has been developed and validated in people with type 2 diabetes, people with type 1 diabetes and people without diabetes.
Description: Labeled triple tracer